difficult. one of those things is the pressure in the suit itself. everything, every time we grab something with our hand or move we have to fight against the pressure of our suit. and those suits when you put all the tools on it and all the equipment, they could be up to 350 pounds. obviously in space, they're weightless but we're still moving that mass around and still have to deal with that. it really is a very fatiguing, physically fatiguing adventure out there in space when you're on a space walk. >> ron, tell us about that because you've actually had that experience for those of us who couldn't even imagine what it's like, give us a sense why that is so important that you have that -- that the liquid stays out of the suit because you had the italian astronaut nearly drowning after a space helmet filled with water. describe why that's so important and what is it like. >> one of the things we're concerned about on a walk is keeping the astronauts cool. because you're doing all that work and there's nowhere for the heat to go. so we have cooling systems within the space suit and basically we're wearing long